Change speed system



J. W. HALE I CHANGE SPEED SYSTEM May 7, 1940. 2,199,993

Original Filed March 4, 1936 Z SheetS-ShQet 1 all/enter Jesse WHale May 7, 1940. w, HALE 2,199,993

CHANGE SPEED SYSTEM Original Filed March 4, 1936 5 Sheets-Sheet 3 Inventor Jesse WHaIe mama May 1, 1946 UNITED STATES 4 CHANGE SPEED SYSTEM Jesse W. Hale, Newton Center, Mass.

Befiled for abondoned application Serial No. 66,995, March 4, 1936. This application July 19, 1937, Serial No. 154,429

19 Claims.

This application is a refile of abandoned application Serial No. 66,995, filed March 4, 1936.

My present invention relates to improvements in change speed systems utilizing the shaftconverting means'disclosed in my copending: application, Serial No. 731,089, filed June 18, 1934.

While the use of such a device in automobiles aflords the best illustration of its adaptability there are many other instances when the ratio between the driving and driven shafts can be automatically controlled with substantial advantage beyond the resulting convenience;

In my present invention I have utilized fluid pressure as the operating medium and have included novel modifications in the unit and in the system which relate both to effectiveness of operation and to different uses to which my invention is well adapted.

In the drawings I have shown illustrative embodiments of my invention'and throughout the drawings and specification the reference numerals indicate corresponding parts.

In the drawings- Fig. 1 is partly section view of my device.

.' Fig. 2 is section along the lines 2-2 of Fig. 1.

Fig. 3 illustrates a reversing unit. I

Fig. 4 is a section along the lines 4-4 of Fig. 1.

Fig.5 shows a novel main clutch.

Fig. 6 is a section along the lines 9-6 of Fig. 5. Fig. 7- illustrates a modified control for the change speed unit.

Fig. 8 is a partly sectioned side view of a modifiedcontrol for the fluid pressure.

Fig. 9 is a'view of Fig. 8 along the lines 99 of Fig. 8.

Fig. 10 is a fragmentary view of the shaft and valve, and

Fig. 11 is a view along the lines ll-ll of Fig. 8- I t x -A gear transmission system such as is indicated in the accompanying drawings may be provided with a housing I having an axial port 2 casing H is slidably mounted for rotation independently of the drive shaft 3 and the driven shaft 5. The gear casing ii is provided with an 55 annular hub l2 and a; rearwardly disposed annular flange Ila. Bushings are indicated at I3 for the hub -,I2 and the casing ll.

Within the hub I2 is a clutch member shown as of conventional roller type R, as suggested in Figs. 2 and 4. As long as the casing II is rotated oppositely to the drive shaft 3 or at the same or lesser speed, the rollers R will travelwith the casing hub I2 freely over the shaft 3, but if the casing Ii tends to reverse its direction of travel, or its speed of rotation tends to become faster than that of the shaft 3, the clutch R acts toprevent such motion or reduces the speed of the casing il to the speed of the shaft. The part played by this clutch R, aswell as the one-way clutches l9 and 2|, later to be'described, .15

one-way clutch l9 (see Fig. 4) of the same generalbohstruction as the first clutch II, which is 25 provided to lock the casing il through the hub l2 to the annular hub ll of the gear H as long as the casing Ii is rotated in a direction opposite to that of the shaft l3.

The idler pinion gears it which are rotated :30

by the rim gear l5 mesh with a gear 29 which is free on the shaft 3, andserve to rotate the gear 29, when in. operation, in the same direction as the drive shaft 3. The gear 29 is provided with an indicated one-way clutch 21 which locks 35 the gear 29 on the shaft 3 when its speed of rotation tends to be greater than that of the shaft 3.

The locking of the gear 20 by the clutch 2t limits the reverse direction trend of the idler 40 assembly, gear casing II, and step gear l9 depending upon relative ratio. The ratio of gears l5 and 29 may be assumed to be, for example, on a one to four ratio. Assuming that the ratio between the gears 9, 9 and I9 be, for example, two to one, and the connected parts be stationary, the speed of the driven shaft 5 would be one-half the speed of the drive shaft 3. But with the assembly, the gear casing II and the step gear l9 are now rotating reversely and the ultimate speedpf the driven shaft 5 will be controlled by'the'gear 29 which cannot rotate faster than the drive shaft 3. In otherwords, the ratio between the casing H and the gear 29 is one to four when the casing II is rotating reversely to the drive shaft 3, but as, however, the gear 20 cannot rotate faster than the drive shaft 3, the

reverse rotation of the casing II is limited and the driven shaft is rotated at a four to one ratio providing a slow forward drive suitable for first speed.

The rim gear member l carries on its outer surface an annular spline type clutch 22 adapted to engage with a similarclutch member 23 mounted in shoulder blocks 23a. on the casing I. The annular hub IT on the gear l5 and the casing H are spaced by thrust bearings indicated at 24.

While any type of clutch may be used, my invention is illustrated with the type of clutch shown in Figs. 1 and 2 so that any question of clutch slipping may be ignored and at the same time (as will appear later from other aspects of my invention), with a cushioned engagement.

The gear member |5 may be moved longitudinally of the shaft 3 with the gear casing II and thereby effect an interlock of the splines 22 and 23, whereupon the casing II will be held stationary to establish a two to one ratio, potentially in the gear system providing a suitable second speed. With this connection, the indicated oneway clutch 2| which held the gear 26 to the shaft 3 is released, permitting free rotation of the drive shaft 3 within the gear 20.

The driven shaft 5 is formed, preferably, with an enlargement 40 which carries a cylinder member 4| disposed with its open end towards the casing Within the cylinder member 4| is a piston 42 which includes a hub 43 having an upturned end 44 between which and the up turned end'of a bushing |'3 for the casing II are positioned bearings indicated as at 32. Slidably mounted on the hub 43 is a second piston 45 under the influence of a spring 46 backed by the upturned end 44 of the hub 43. The piston 45 carries clutch members 41 adapted to engage like'members 48 on the rear of the casing These clutches are similar in construction to the clutches 22 and 23 before described.

From any pressure source such as the crank case (not shown) a conduit 50 controlled by a valve 5| leads into a hub 52 surrounding the shaft 3 while a conduit 5|] permits the circulation of the fluid when the valve 5| closes the flow of fluid to the hub 52,. The shaft 3 is grooved within the hub 52 to define a fluid receiving conduit and is connected to the axial bore 53 as by a Y connection 54. The driven shaft 5 has a similar axial bore 55 which in the enlargement 46 is provided with a radial discharge 56. While I may deliver fluid in a similar manner directly to the driven shaft 5, I prefer to deliver it in the manner described to provide a positive lubrication. Rearwardly of the discharge 56 I provide a conduit 51 through the shaft portion 40 disposed to discharge through the cylinder 4| against the piston 42. Spaced rearwardly from the conduit 51 is a second conduit 58 passing through the cylinder 4| as shown clearly in Fig. 1 to discharge within the cylinder 4| and to actuate the piston 45 which is splined in the cylinder 4| as is indicated at 59. Slidably mounted on the enlarged portion 40 of the driven shaft 5 is a valve 60 having an annular recess of sufficient length. to permit the port 56 to be connected to both the conduit 51 and to the conduit 58 successively. The cylinder 4| carries a governor 6| one arm 62 of which is adapted to bear against a forwardly curved flange 63 on the valve 66. A consideration of 'Fig. 1 will indicate the operation of the governor. When the governor is at rest, the extended curved flange 63 of the valve 6|] rests against the governor 6| at a point near its fulcrum. It willalso be noted that the governor arms 62 are curved so that a. definite cam action results. Initial movements of the governor may be contrasted to its subsequent movements for when the outer tip of the governor arms 62 engage the curvedportion .of the flange 63, a more rapid movement results to balance the increased centrifugal force by lengthening the distance from the governor fulcrum to the point where the arm 62 contacts the valve flange 63. While a uniformly curved outer end of the valve flange is shown for reasons of simplicity with corresponding shaped governor arms, these surfaces may be irregular to maintain operating conditions as required.

The valve 60 is under the influence of a spring 64 the resistance of which is adapted to be increased by a ring 65 slidably mounted on the hub 66 overlying the driven shaft 5 within the casing Suitable thrust bearing 61 separate the enlarged portion .40 of the shaft 5 from the hub 66 while the thrust bearings 66 separate the spring 58 and the ring 65. I

It will be understood that the spring 58 coul be provided with a non-slidable anchor but the arrangement permits the resistance of the spring 'to be varied to affect the action of the governor 6| as will subsequently be more fully described.

The ring 65 is under the control of. a fork 69 carried by the shaft III which is in turn rotated by the lever 1| to which is pivotally secured a lever 12 adapted to be actuated by the lever 13 under the control of the operator as suggested by the brake l4 and accelerator'15. The lever I3 is pivoted as at P so that on movement of the accelerator or brake I4, the lever I2 is thrust to the right as viewed in Fig. 1 with the result that the ring 65 will be thrust to the left.

The operation of that part of my device thus far described may at this time be conveniently described. Assuming the main clutch to be engaged and the valve 5| open to permit fluid under pressure to flow through the device to the valve 66 the various gear ratio changes take place as follows.

When the vehicle is initially moving the resistance of the shaft 5 is very great and as a result the gear l0 and the case M develop a rotation counter to that of the drive shaft 3. Through the one way clutch I9 the rim gear I5 is carried therewith. The gear is accordingly rotated in the same direction as the drive shaft 3 and in fact locked thereto reducing 'the rotation of the housing H and causing a low v connected. In this position it will be noted that detents 16 tend to hold the governor in that position until the speed'thereof has materially increased. Fluid under pressure is now admitted directly against the piston 42 tending to move it forwardly.

Through. the hub 43 the gear casing is similarly carried and with it the rim gear |5 until the clutch members 22 and 23 are interengaged.

In this position, rotation of the rim gear I5 and the casing II counter to that of the drive shaft 8 is prevented and the gear connection 8, I0 and 8 will operate to effect a speed suitable for second speed. Further increase in speed of the governor will overcome the resistance of the detents 16- and will tend to slide the valve 60"further until the conduit 58 is also connected to the port 56 and fluid is free to enter between the-pistons 42 and 45. When the pressure therein is effective to overcome the spring 46 the piston 45 moves carrying the clutch members 41 and 48 into engagement locking the casing II to the cylinder 4| to eflect a suitable high speed.

It will be noted that because of the nature of the clutches 22 and 28 and 41 and 48 it is desirable to eflect a positive disengagement thereof such as is provided by the spring 41 and for .that reason I use the gears 8 and I0 as spiral gears so that aslight rearward thrust tendency of the casing II is created which through the overhang 11 is adapted to contact on rearward movement, the flange 18 on the hub of the ring gear I5 (see Figs. 1 and 4).

Similarly because of the nature of these clutches I have found it necessary for eflicient operation to use the form of clutch shown in Figs. 5 and 6. This clutch might. be conveniently housed in a casing IOI which .is provided with axial ports I02 and I03 for the driving portion I04 and for the driven portion 3 of the shaft respectively. Suitable bushings indicated as at I05 are, of course, provided. The driving portion I04 includes a hollow enlarged head I06 adapted to receive the flanged head I01. of the slidable clutch actuating member I 08. The head I06 is provided with a flanged end provided with a plurality of bores as at I09 to receive pairs of ball bearings 0, suitable antifriction devices III. which are separated by the spring II2. Forwardly of'the flange of the head I06 the governors II3 are positioned. These include arms I I4 which extend through the apertures I I5 in the head I06 into an annular groove H6 in the flange I01. Rearwardly of the flange I01 the member I08 is provided with a sloped shoulder H1. The shaft 3 is provided with a hollow cylindrical head II8 overlying the flange I06 carried by the driving portion I04. The inner surface of the cylinder II8'is provided, as is shown most clearly in Fig. 6, with a series of detent surfaces II9 into which the spring II2 force the ball bearings IIO to effect engagement.

The casing IOI is formed with an opening I20 and as indicative or suggestive of one possible basis of control, I have shown a lever I2I pivoted as at I2I in control of a recessed slide I 22 effective to hold before the motor is started, the governor H2 in inactive position thereby permitting the clutch provided between the driving and he driven members to slip.

Assuming the clutch mechanism just described to be disengaged so that the governor II3 may be carried outwardly by centrifugal force, it will be seen that as the speed of the drive shaft increases the flanged head I01 is drawn forward carrying the shoulder I I6 forwardly to compress the spring IIO to establish a more positive interlock between the driving portion I04 and the cylinder II8 so that I may cushion any shock from the engagement of positive clutching means such as those that I have used for illustrative purposes.

In Figs. 8 to 11, I have shown novel means by which the valve movements may be dominated without pressure against the actuating operator controlled mechanisms (shown for' purposes of illustration as the brake 14 and the accelerator In this modification, the governors I24 are pivoted to lie parallel to the head of the cylinder 4i. A sleeve I 24 surrounding the shaft portion 40 includes a gear portion I25 in mesh with which are the toothed portion I24" of the governors I24. 2

The sleeve I25 is recessed to receive balls I26 which are mounted therein and 'in the grooves I26 in the slide valve 60 which through a connection indicated at I21 is free to rotate though slidably under the influence of the lever arm 10.

It will be noted that the valve 60 includes two oppositely disposed raised portions I28 and I29. As will be apparent from Figure 9, the actionof the governors I24 on the sleeve I25 as they are effected by centrifugal force rotate the valve 60 in a direction counter to that of the driven shaft, the raised portions I28 and I29 are formed to present a forwardly extended tapering surface (see Figs. 8 and 10). I have shown the conduits leading to the cylinder M as at 51 and 58.

In operation, the action of the governors I24 are effective to rotate the valve 60 slowly to cover the ports 51 and 58, successively. Actuation of the operator controlled machine is eflective to slide this valve (i0 forwardly so that the connection of the ports 51 and 58 will be delayed to permit gear ratio changes to be effected and put suggest a different basis of control as may.

be best illustrated by its use in association with a compressor wherein it is desired to regulate the speed of the compressor with relation to a desired maximum pressure in a supply tank.

My invention is particularly adapted for such purposes as will be apparent from Fig. 7.

The lever 1I permitting in Figs. 1 and 8 the dominance of the governor by the operator may, as in Fig. 7, be controlled by fluid or other pressuresthrough conduit I40 from the pressure discharge of compressor, pump, or other equipment. From this source a line I40 discharges into a cylinder I4I to actuate a piston I42 against the influence of a spring I43 the tension of which may be adjusted by the plug I43. The connecting rod I44 of the piston I42 is pivotally connected to the lever 1I and extends into a recess I45 of a rod I46 to establish after predetermined movements of the piston a connection of the extension rod I46 and the piston rod I44. This extension rod I46 is pivotally connected to a lever I41 controlling the throttle valve indicated at T.

I have indicated at I48 a stop towards which the lever I41 is drawn by the spring I48 when not under the control of the piston I42. This stop may be adjusted to permit the throttle to be controlled as desired.

Assuming the source of pressure to be great the load on the compressor will, of course, be materially increased and as the pressure increases the spring I43 in the cylinder is overcome and the piston I42 is partially expelled causing the actuation of the lever 1| to aflect' 75 tation'of the driven shaft I5I results.

regulated to take care of its correspondingly lighter load. Throttles such as indicated at T include means to adjust them to establish the desired idling condition so that the engine will not stall. In accordance with my invention, the throttle T is not affected until the lowest gear ratio is established between the shafts.

In Fig. 3 I have shown an effective reversing mechanism that is in keeping with the general simplicity of .my invention and that may be used in a system including. a device to cushion the shock of engagement of such clutch as there shown.

A casing I may conveniently be secured to the rear of the casing I. Within this casing the driven shaft 5 is divided into a driving portion'5 and a driven portion I5I adapted to be connected.

through the medium of gears I52 and I53 both meshing with a pinion gear I54 pivotally mounted in a freely rotatable casing I55. Bushings are indicated at I553. The gear I53 is provided with suitable clutch surface such as the indentations I56 into which the teeth I 51 of a sleeve member I58 are adapted to-interlock. The sleeve member I58 is adapted to engage by a similar clutching means the hub member I59 surrounding the'driven shaft IN.

This sleeve I58 is splined as indicated at I58 to the housing I55 and may be moved by means of the fork I mounted on a shaft I BI which may be turned by any actuating means (not shown). When the lever I60 is moved to carry the sleeve into a position eflective to interlock the clutch surfaces I56 and I51, the housing I55 rotates with the driven shaft I5I as in forward speed while if the fork or lever I60 is moved in the opposite direction until the other clutch interlocks the sleeve I58 and the hub member I59 a reverse ro- This simple mechanism makes possible a very effective reversing mechanism.

The casings IIII and I50 may be integral with the casing I and as fluid must be returned to the source (not shown) suitable outlet or connecting ports P are shown.

If" desired, and if thesource of power is adequate, the valves 60 or 60 may be normally positioned to connect the conduits 56 and 51 so that the load will be assumed at second speed unless the torque is too great. If the torque is too great, further movement of the accelerator positions the valve to close the conduit 51 thus establishing the low speed ratio. ,With the valve positioned as indicated the accelerator may be termed the dominant factor. I

It will be seen that my present invention is well adapted to solve problems presented by a variety of operation conditions.

What I therefore claim and desire to secure by Letters Patent is: I

1. In a change speed device, a drive shaft, a driven shaft, an idler assembly connecting said shafts and including portions slidable and independently rotatable with reference to said shafts, means adapted to control said portions to effect desired ratios between said shafts, said means including a stationary clutch element to prevent rotation of said portions counter to said drive shaft and a clutch adapted to connect said portions with said driven shaft, a pair of pistons concentrically mounted on said driven shaft, a sourceprevent rotation of said portions counter to said drive shaft and a clutch including a member slidably splined to said driven shaft and adapted I to connect said portions therewith, fluid pressure operated means adapted to carry said portions into contact withsaid stationary clutch element and said second-mentioned clutch into engagement with said portions, and a control for said pressure means dependent on driven shaft speeds and on operating conditions desired.

3. In a change speed device, a drive shaft, a driven shaft, an idler assembly connecting said shafts and including portions slidable and independently rotatable with reference to said shafts, means adapted to control said portions to effect desired ratio changes, said means comprising a stationary clutch element adapted to prevent rotation of said portions counter to said drive shaft, a cylinder on said driven shaft, a pis ton in said cylinder including a hub adapted to move said portions into contact with said stationary clutch element, a second piston slidably mounted on said hub and splined in said cylinder, said second named piston and said portions including clutch surfaces to cause on interengage ment the rotation of said portions with said driven shaft, fluid pressure delivery means to each piston, said fluid delivery means including controls predicated on driven shaft speed and desired operating conditions.

4. In a change speed device, a drive shaft, a driven shaft, means adapted to connect said shaftsat different ratios, a pair of fluid pressure operated pistons adapted to cooperate with said means to effect desired ratio changes, a fluid conduit through said drive shaft and said driven shaft to the surface thereof, a conduit to each of said pistons including portions extending from said driven shaft surface through said driven shaft, a slide valve adapted to connect said conduit with said delivery conduit, a governor to operate said valve, and pressure controlled means to affect said governor action as desired.

5, In a change speed device, a drive shaft, a driven shaft, means adapted to connect said shafts at different ratios, a pair of fluid pressureoperated pistons adapted to cooperate with said means to effect different ratios between said shafts, a source of fluid underpressure comfnunicating with the surface of said driven shaft, a conduit to each of said pistons through said driven shaft from the surface thereof, a slide valve adapted to effect communication between said pressure source and said conduits, a governor responsive to the speed of the driven shaft to 6. In a change speed device, a drive shaft, a

driven shaft, means adapted to connect said, shafts at different ratios, a pair of'fluid pressure operated pistons. adapted to cooperate with said means to effect different ratios between said shafts, a source of fluid under pressure communicating with the surface of said driven shaft, a conduit to each of said'pistons through said driven shaft from the surface thereof, a slide valve adapted to eflect communication between said pressure source and said conduits, a governor responsive to the speed of the driven shaft to operate said valve, and means to vary the operation of said valve as required, said'second named .means comprising a member adapted to slide said valve against the action of said governor, a source of fluid 'under pressure responsive to the driven shaft torque, a cylinder, a conduit from said source 'to said cylinder, a piston in "said cylinder, a spring adapted to be compressed by said piston as said piston is actuated by said pressure, said piston being in control of said member.

7.'In a change speed device, a drive shaft, a

driven shaft, means adapted to connect said shafts at different ratios, 9.- pair of fluid pressure operated pistons adapted to cooperate with said means to effect different ratios between said shafts, a source of fluid under pressure communicating with the surface of said driven shaft, a conduit to each piston, a valve slidably mounted on said driven shaft, said valve being adapted to effect communication between said source and said conduits, a governor responsive to the speed of the ,driven shaft to operate said valve, and means to vary the operation of saidgovernor as required, said second named means comprising a member adapted to slide saids valve against the action of said governor, a source of fluid under pressure responsive to ''the driven shaft torque, a cylinder, a conduit fromsaid source to said cylinder, a piston in said cylinder, a spring adapted to be compressed by said piston as said piston is actuated by said pressure, means to vary the tension of said spring and said control of said member.

8. In a change speed device, a drive shaft, a driven shaft, means adapted to connect said shafts at different ratios, 9. pair of fluid pressure operated pistons adapted to cooperate with said means to effect different ratios between said shafts, a source of fluid under pressure communicating with the surface of said driven shaft, a conduit to each piston, a valve slidably mounted on said driven shaft, said valve being adapted to effectcommunication between said source and said conduits, a governor responsive to the speed of the driven shaft to operate said valve,. and means to vary the operation of said governor as required, said second named means comprising a member adapted to slide said valve against the action of said governor, a source of fluid under pressure responsive to the driven shaft torque,

a cylinder, ,a conduit from said source to said cylinder, a piston in said cylinder, a spring adapted to be compressed by said piston ,as said pissaid pressure, said piston being in control of said member, a valve in control of a fuel line and bein under the control of said piston.

9. In a change speed device, a drive shaft, a driven shaft, means adapted to connect said shafts at different ratios, a pair of fluid pressure piston being in operated pistons adapted to cooperate with said means to efl'ect different ratios between said shafts, a .source of fluid under pressure communicating with the surface of said driven shaft,

a conduit to each piston, a valve slidably mounted on said driven shaft, said .valve being adapted to effect communication between said source and said conduits, a governor responsive to the speed action of said governor, a source of fluid underv pressure responsive to the driven shaft torque,

a cylinder, a conduit from said source-t0 said cylinder, a piston in said cylinder, a spring.

adapted to be compressed by said piston asrsaid piston is actuated by the said last mentioned fluid under pressure, said piston beingin control of said member, a valve in control of a' fuel line, means in control of said valve, said means being adapted to be actuated on predetermined movement of said piston.

,10. In a change speed device, a drive shaft, a driven shaft, means adapted to connect said shafts at different ratios, a pair of fluid pressure operated pistons adapted to cooperate with said means to effect different ratios between said shafts, a source of fluid under pressure com municating with the surface of said driven shaft, a conduit to each piston, a valve slidably and rotatably mounted on said driven shaft, said valve being formed to cover said conduits successively on partial rotation including a dishaft, said governors and said sleeve having interengaging gear portions, a lever, said lever andsaid valve including a connection permitting free rotationof said valve, said lever being adapted to be actuated to slide said valve to vary the extent of the rotation of said valve necessary to efl'ect communication between said conduits. I x i I 11. In a change speed device, a drive shaft, a driven shaft, means adapted to connect said shafts at different ratios, a pair of fluid pressure operated pistons adapted to cooperate with said means to effect different ratios between said shafts, a source of fluid under pressure oommunicating with the surface of said driven shaft, a conduit communicating with each piston, a valve slidably mounted on said driven shaft, said valve being adapted to effect communication between said source and said conduits, 'a governor responsive to the speed of the driven shaft to operate said valve and operator controlled means to vary the operation of said governor as required by operating conditions.

12.'-In a change speed device, a drive shaft, a driven shaft, an idler assembly connecting said shafts and including portions independently r0- tatable with reference to said shafts, means tolimit and means to prevent retrograde rotation of said assembly, and means to rotate said assembly with said driven shaft, fluid pressure operated means to operate said second and third named means, and means in control of said fluid pressure operated means, said means compris-r ing a valve, a governor to actuate said valve, and

'said driven shaft, a piston in said cylinder, said piston including a hub in contact with said slidable member, a second piston slidably mounted on said hub and splined in said cylinder, clutch elements carried by said second piston and said slidable member, a source of fluid in communication with said pistons, a valve in control of said fluid, and means responsive to the speed of said driven shaft to actuate said valve, and

a compressible member to oppose the action of said speed responsive means.

14. In a .change speed device, a drive shaft, a driven shaft, means adapted to connect said shafts at different ratios, said means including a slidable member mounted on said driven shaft for independent rotation, a cylinder carried by said driven shaft, a piston in said cylinder, said piston including a hub in contact with said slidable member, a second piston slidably mounted on said hub and splined in said cylinder, clutch elements carried by said second piston and said slidable member, a source of fluidin communication with said pistons, a valve in control of' said fluid, means responsive to the speed of said driven shaft to actuate said valve, a. compressible 'member to oppose the action of said speed responsive means, and detent means to delay the action of said speed responsive means.

15. In a change speed device, a drive shaft,

a driven shaft, an idler assembly adapted to connect said shafts and being slidable and adapted to be independently rotatable with reference to said shafts, said assembly including a gear on each of said shafts, and an idlergear in mesh with each of said shaft gears, means to hold said assembly against rotation, said means including a pair of jaw toothed clutch elements, one of said clutch elements being slidable, means to slide said assembly and said slidable clutch element to effect a clutch engagement, and means to disengage said clutch elements, said last mentioned means comprising a member carriedby said slidable clutch element and a member adapted to engage said first named member on rearward movement of said assembly, and at least two of the meshed gears of said assembly having their teeth disposed to urge said assembly rearwardly.

16. In a change speed device, a drive shaft, a driven shaft, an idler assembly adapted to connect said shafts and to rotate independently thereof, means to limit retrograde rotation of said assembly beyond a predetermined ratio relative to said drive shaft to establish a low driven shaft speed, "means to hold said assembly against rotation to establish an intermediate driven shaft speed, means to rotate said assembly with said driven shaft to establish a high driven shaft 'speled, fluid pressure operated means to ac-. tuate said second and third-named means in predetermined order.

1'7. In a change speed device, a'drive shaft, a driven shaft, an idler assembly adapted to connect said. shafts and to rotate independently thereof, means-to limit retrograde rotation of said assembly beyond a predetermined ratio relative to said drive shaft to establish a low driven shaft speed, means to hold said assembly against rotation to establish an intermediate driven shaft speed, means to rotate saidassembly with said driven shaft 'to establish a high driven shaft speed, each of said second and third-named" of said pistons, a valve to efi'ect communication between said source and said pistons comprising amember having an inlet port and a pair of outlet ports and a member slidable and rotatable with reference to said first-named member to connect said ports in predetermined order, speed responsive meansto rotate said second-named member and includinga slidable interconnection therewith, and means moveable with said control to'sl'ide said member, the extent of the rotation of said second-named member to connect said ports being determined by the position of said second-named member effected by'said last-' named means.

19. In a change speed device, a drive shaft,

,a driven shaft, means to connect said shafts at different ratios, hydraulically operated means to efiectestablishment of said different ratios, a valve in control of said hydraulically operated means, speed responsive means ,to actuate said valve and means to vary the operation of said valve as required, said last named means comprising a member to actuate said valve against the action of said governor, a source of pressure 8 responsive to the driven shaft torque, a cylinder, a conduit from said source to said cylinder, and a piston in said cylinder toactuate said member and a spring adapted to be compressed by said piston.

' JESSE W. HALE. 

